Re: [PATCH] x86: 46 bit PAE support

From: H. Peter Anvin
Date: Thu May 07 2009 - 10:29:21 EST


Ingo Molnar wrote:
>
> Yes, struct page is ~64 bytes, and 64*64 == 4096.
>
> Alas, it's not a problem: my suggestion wasnt to simulate 64 TB of
> RAM. My suggestion was to create a sparse physical memory map (in a
> virtual machine) that spreads ~1GB of RAM all around the 64 TB
> physical address space. That will test whether the kernel is able to
> map and work with such physical addresses. (which will cover most of
> the issues)
>
> A good look at /debug/x86/dump_pagetables with such a system booted
> up would be nice as well - to make sure every virtual memory range
> is in its proper area, and that there's enough free space around
> them.
>

We're working on simulating this at Intel. We should hopefully be able
to test this next week.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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